This research proposal centers on the basic action of lead on representative living procaryotic and eucaryotic organisms. The study is devoted to defining the primary mechanisms of lead's actions at the cellular and subcellular levels as well as on the effects of lead on individual cellular chemical components. This proposal contains studies on the effects of lead on ribosomal-RAA and aliphatic ketone biosynthesis to advance one's knowledge towards defining the mechanism(s) by which lead influences the reduction of total bacterial cellular lipid biosynthesis. The biosynthesis of teichoic acids will also be studied to measure its relationship with lead and to further test the proposed function of teichoic acid as an agent for metal ions exchange in outer regions of bacterial cells. In conjunction with this study we propose to study bacterial cells resistance to lead on the basis that lead is not immobilized in lead resistant cells. Employing a similar experimental approach for studying the effects of lead on procaryotic systems, experiments are described to determine the effects of lead on eucaryotic lipid biosynthesis in lungs, surfactants, lamellar body fractions, and alveolar macrophages. These studies are conducted in association with cellular ultrastructural changes of the same lead exposed cells.